CST 438 Week 6

WELCOME TO WEEK 6

Learning Journal - CST 438

Write a weekly entry describing important things you learned this week.

     This week I read Chapter 25 on Compute as a Service and learned how Google turned running code into an automated system. For example, instead of rebooting machines by hand when they fail, engineers set up policies to kill and recreate a container or virtual machine automatically after a health check fails. I saw why treating servers as cattle not pets matters. When one node goes down, the system simply stamps out a new instance without any human intervention. Using Linux control groups and namespaces made it possible to safely share machines among different workloads. Writing software for this environment means dividing tasks into small units, storing all important state in durable services such as Spanner or Bigtable, and designing retries so they can run more than once without causing errors. Finally I was struck by the description of the Code Jam team warming App Engine instances before a contest to avoid cold starts and ensure smooth performance.

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